CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME (USD $)	Common Stock [Member]	Additional paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 31, 2008	$ 43,001	$ 22,881,937	$ 85,868,637	$ (20,547,419)	$ (5,239,011)	$ 83,007,145
Cumulative effect of change in accounting principle, adoption of other-than-temporary impairment guidance, net	0	0	246,544	0	(246,544)	0
Comprehensive Income:
Net income	0	0	5,232,835	0	0	5,232,835
Change in unrealized gains (losses) on securities AFS, net	0	0	0	0	1,301,106	1,301,106
Change in funded status of Employers' Accounting for Defined Benefit Pension and Other Benefit Plans, net	0	0	0	0	3,618,614	3,618,614
Total comprehensive income (loss)						10,152,555
Distribution of shares of treasury stock for directors' deferred compensation plan	0	(36,617)	0	34,271	0	(2,346)
Distribution of shares of treasury stock granted for employee restricted stock awards, net	0	(11,287)	0	61,287	0	50,000
Restricted stock units for directors' deferred compensation plan	0	104,929	0	0	0	104,929
Cash dividends declared	0	0	(3,521,685)	0	0	(3,521,685)
Distribution of shares of treasury stock for directors' compensation	0	(58,026)	0	279,716	0	221,690
Sale of shares of treasury stock	0	(74,107)	0	303,627	0	229,520
Purchase of shares of treasury stock	0	0	0	(156,143)	0	(156,143)
Balances at Dec. 31, 2009	43,001	22,806,829	87,826,331	(20,024,661)	(565,835)	90,085,665
Comprehensive Income:
Net income	0	0	10,101,873	0	0	10,101,873
Change in unrealized gains (losses) on securities AFS, net	0	0	0	0	1,006,282	1,006,282
Change in funded status of Employers' Accounting for Defined Benefit Pension and Other Benefit Plans, net	0	0	0	0	(337,972)	(337,972)
Total comprehensive income (loss)						10,770,183
Distribution of shares of treasury stock for directors' deferred compensation plan	0	(661,102)	0	650,324	0	(10,778)
Distribution of shares of treasury stock granted for employee restricted stock awards, net	0	(149,303)	0	150,446	0	1,143
Restricted stock units for directors' deferred compensation plan	0	111,772	0	0	0	111,772
Cash dividends declared	0	0	(3,520,584)	0	0	(3,520,584)
Distribution of shares of treasury stock for directors' compensation	0	(44,677)	0	258,906	0	214,229
Distribution of shares of treasury stock for employee compensation	0	(15,537)	0	70,537	0	55,000
Sale of shares of treasury stock	0	(25,860)	0	153,360	0	127,500
Purchase of shares of treasury stock	0	0	0	(425,567)	0	(425,567)
Balances at Dec. 31, 2010	43,001	22,022,122	94,407,620	(19,166,655)	102,475	97,408,563
Comprehensive Income:
Net income	0	0	10,537,755	0	0	10,537,755
Change in unrealized gains (losses) on securities AFS, net	0	0	0	0	2,326,042	2,326,042
Change in funded status of Employers' Accounting for Defined Benefit Pension and Other Benefit Plans, net	0	0	0	0	(3,869,895)	(3,869,895)
Total comprehensive income (loss)						8,993,902
Restricted stock awards	0	28,141	0	0	0	28,141
Distribution of shares of treasury stock for directors' deferred compensation plan	0	(7,364)	0	7,310	0	(54)
Distribution of shares of treasury stock granted for employee restricted stock awards, net	0	(226,360)	0	225,350	0	(1,010)
Forfeit of restricted stock awards	0	27,762	0	(27,762)	0	0
Restricted stock units for directors' deferred compensation plan	0	80,083	0	0	0	80,083
Cash dividends declared	0	0	(4,316,475)	0	0	(4,316,475)
Distribution of shares of treasury stock for directors' compensation	0	(33,831)	0	265,262	0	231,431
Distribution of shares of treasury stock for employee compensation	0	(6,140)	0	61,140	0	55,000
Sale of shares of treasury stock	0	(25,090)	0	242,610	0	217,520
Purchase of shares of treasury stock	0	0	0	(501,299)	0	(501,299)
Issuance related to FOFC Merger	10,100	23,723,538	0	0	0	23,733,638
Balances at Dec. 31, 2011	$ 53,101	$ 45,582,861	$ 100,628,900	$ (18,894,044)	$ (1,441,378)	$ 125,929,440